A well known technique for cutting metal includes the use of a carbon arc electrode. A low voltage, high current source is applied between the work piece and the electrode. A workman positions the electrode to establish an arc between the electrode and the work piece. The arc creates substantial heat, melting away metal where the arc contacts the metal work piece creating molten metal. By use of a jet of air the molten metal is blown away to expose further unmolten metal making up the work piece so that metal can be removed from the work piece as the workman skillfully positions the electrode.
In order to effectively accomplish cutting metal using this technique, a holder is required to perform three basic functions. First, to hold a carbon arc electrode in a way so that it can be easily manipulated by a workman and wherein the length of the electrode extending from the holder can be easily adjusted. Second, to provide means of maintaining a low electrical resistant connection between the holder and electrode. Third, to direct air along the electrode to blow away molten metal formed in the cutting process. It is important that the holder be as light as possible and yet sturdy enough to support a carbon arc electrode in the harsh environments in which it is used.
For background information relating to holders for carbon arc electrodes, reference may be had to the following previously issued United States patents:
______________________________________ U.S. PAT. NO. INVENTOR TITLE ______________________________________ 4,045,649 Moss et al Holder For Carbon Arc Electrodes 4,150,276 Moss Holder For Air Carbon Arc Electrode 4,761,531 Moss Torch With Improved Air Flow 4,948,935 Moss Apparatus For Use With A Carbon Arc Torch To Retain Short Electrodes ______________________________________